Index: sys/ddb/db_command.c
===================================================================
--- sys/ddb/db_command.c
+++ sys/ddb/db_command.c
@@ -479,7 +479,15 @@
 		db_enable_pager();
 	    else
 		db_disable_pager();
+
+	    db_lex_wspace = ((cmd->flag & CS_LEX_SPACE) != 0);
+	    db_cmd_radix = -1;
+
 	    (*cmd->fcn)(addr, have_addr, count, modif);
+
+	    db_lex_wspace = false;
+	    db_cmd_radix = -1;
+
 	    if (dopager)
 		db_disable_pager();
 
Index: sys/ddb/db_lex.h
===================================================================
--- sys/ddb/db_lex.h
+++ sys/ddb/db_lex.h
@@ -45,6 +45,7 @@
 int	 db_read_token(void);
 void	 db_unread_token(int t);
 
+extern bool		db_lex_wspace;
 extern db_expr_t	db_tok_number;
 #define	TOK_STRING_SIZE		120
 extern char	db_tok_string[TOK_STRING_SIZE];
@@ -84,5 +85,6 @@
 #define	tSTRING		32
 #define	tQUESTION	33
 #define	tBIT_NOT	34
+#define	tWSPACE		35
 
 #endif /* !_DDB_DB_LEX_H_ */
Index: sys/ddb/db_lex.c
===================================================================
--- sys/ddb/db_lex.c
+++ sys/ddb/db_lex.c
@@ -42,6 +42,8 @@
 #include <ddb/ddb.h>
 #include <ddb/db_lex.h>
 
+bool		db_lex_wspace;
+
 static char	db_line[DB_MAXLINE];
 static char *	db_lp, *db_endlp;
 
@@ -148,6 +150,14 @@
 char	db_tok_string[TOK_STRING_SIZE];
 
 db_expr_t	db_radix = 16;
+/*
+ * When db_cmd_radix is not -1, it overrides auto-detection, as well as
+ * user-specified db_radix, in db_lex() tNUMBER.
+ *
+ * db_cmd_radix is set by DDB command(s) and its value is scoped to that
+ * command only; when the command completes, it is reset to -1.
+ */
+db_expr_t	db_cmd_radix = -1;
 
 void
 db_flush_lex(void)
@@ -160,20 +170,26 @@
 static int
 db_lex(void)
 {
-	int	c;
+	int	c, n;
 
 	c = db_read_char();
-	while (c <= ' ' || c > '~') {
+	for (n = 0; c <= ' ' || c > '~'; n++) {
 	    if (c == '\n' || c == -1)
 		return (tEOL);
 	    c = db_read_char();
 	}
+	if (db_lex_wspace && n != 0) {
+	    db_unread_char(c);
+	    return (tWSPACE);
+	}
 
 	if (c >= '0' && c <= '9') {
 	    /* number */
 	    int	r, digit = 0;
 
-	    if (c > '0')
+	    if (db_cmd_radix != -1)
+		r = db_cmd_radix;
+	    else if (c > '0')
 		r = db_radix;
 	    else {
 		c = db_read_char();
Index: sys/ddb/ddb.h
===================================================================
--- sys/ddb/ddb.h
+++ sys/ddb/ddb.h
@@ -120,6 +120,8 @@
 #define	CS_OWN		0x1	/* non-standard syntax */
 #define	CS_MORE		0x2	/* standard syntax, but may have other words
 				 * at end */
+#define	CS_LEX_SPACE	0x4	/* Switch the lexer to explicitly yield
+				   whitespace (tWSPACE) during cmd. */
 #define	CS_SET_DOT	0x100	/* set dot after command */
 	struct command_table *more; /* another level of command */
 	LIST_ENTRY(command) next; /* next entry in the command table */
@@ -188,6 +190,7 @@
 extern int db_store_count;
 extern volatile int db_pager_quit;
 extern db_expr_t db_radix;
+extern db_expr_t db_cmd_radix;
 extern db_expr_t db_max_width;
 extern db_expr_t db_tab_stop_width;
 extern db_expr_t db_lines_per_page;